Isopropyl alcohol vapor dryer system

摘要

Microprocessor controlled isopropyl alcohol vapor dryer system for robotic drying of wafer cassettes containing wafers or substrates. A wetted wafer or substrate is robotically placed into a virgin isopropyl alcohol vapor zone. The wetted surface and free-moving contaminants are replaced by a layer of isopropyl alcohol (IPA) which condenses on the surface. The dryer then robotically moves the IPA coated wafer or substrate into an upper cooling zone causing the isopropyl alcohol layer to flash off of the substrate surface, leaving the surface completely dry to a molecular level. IPA vapors are heated at the bottom of a quartz tank and maintained as a vapor by electric heating panels surrounding the quartz tank. A stainless steel cooling jacket surrounds the upper outer region of the quartz tank and between the quartz tank, and a stainless steel containment tank along with a cooling coil delineates a cooling zone about the upper region of the quartz tank where the IPA is flash-cooled from the surface of the substrate. A saucer with opposing curved sections provides for improved vapor blanket generation and regeneration. Cooling coil catch trays catch IPA condensate for channeling to the side walls. The IPA condensate rolls down the walls and is heated and returned in a vapor state or to the sump at an elevated temperature.